This document relates to receiving search queries and providing search results.
A search engine includes one or more computers that receive a search query (for example, a text query from a user device), and, in response, identify resources that satisfy the search query. The search engine provides search results that identity the resources to the user device, which then displays the results in a display device. The quality of search results, defined in some instances in terms of precision and recall, can be affected in part by the specificity of search queries that the search engine receives from the user device and in part by the search methods that the search engine implements.
From the perspective of a user who has provided a search query to a search engine, the relevance of the resources identified by the search engine to the user's informational need can represent a quality of the performance of the search engine. Often, the user may need to periodically refine the search query provided to the search engine so that the search engine can identify more relevant resources. If the resources identified by the search engine do not satisfy the user's informational need, particularly despite periodic refinement, then the user may become frustrated with the search engine.